The broad, long-term objectives of the present research proposal are to electrophysiologically and behaviorally investigate the development of the neurocognitive language-processing system in normal and language- impaired (LI) children so as to establish the identity and timecourse of development of reading-related skills in 5- to 8-year-old beginning readers. Once established, this sort of knowledge can be applied to methods for teaching reading and to design of interventions for reading- disabled children. Electrophsiologically, event-related potentials (ERPs) will be recorded over multiple brain regions as normal and LI children process stimuli designed to activate specific aspects of sensory and language functions; behaviorally, scores on standardized reading tests will measure reading fluency. Three ERP experiments are proposed to investigate (1) the development of auditory and visual, semantic and syntactic sentence-processing in the same normal children and the relationship between ERP measures of these sorts of processes and behavioral reading fluency; (2) the development of basic visual, auditory, and phonological processes in normal children as measured by ERPs, and their relationship to behavioral reading fluency; and (3) the development of basic visual, auditory, and phonological processes in LI children as measured by ERPs, and their relationship to reading fluency and possible deviance from the course of normal development.